Research and commercialization of vehicles with hybrid propulsion systems has increased substantially in recent years. Hybrid-electric vehicles (HEV) in particular have been successfully introduced into the marketplace, and are expected to capture substantial increases in market share in coming years. HEV vehicles may be configured in a variety of ways. Typical configurations include a battery or other energy storage device, and a motor/generator or other mechanism for converting mechanical energy of the vehicle into electrical energy stored in the battery, and/or for using the electrical energy stored in the battery to generate torque for propelling the vehicle.
HEV vehicles typically are capable of operating in different propulsion modes. For example, some HEV vehicles may be operated with the internal combustion engine turned on or turned off. In these vehicles, various control schemes are employed to control whether the engine is turned on or off.
The inventors herein have recognized that such vehicles commonly suffer from problems associated with sub-optimal control of the available propulsion modes. In particular, many HEV systems suffer performance deficits when operated in conditions that tend to produce frequent propulsion mode transitions. Propulsion mode transitions have a “cost” in the sense that there are often control complexities, temporary inefficiencies, NVH issues, etc. with making a transition. The desirability of a contemplated transition is therefore somewhat dependent upon the amount of time that will likely be spent in the new mode.
In one approach, the above issues may be addressed by a method of controlling a hybrid propulsion system of a vehicle, the hybrid propulsion system including an internal combustion engine and an alternate powertrain torque source capable of propelling the vehicle while the engine is turned off, the method comprising of detecting congestion by receiving and analyzing data that is external to the vehicle, and controlling a transition of the hybrid propulsion system between a first propulsion mode and a second propulsion mode based on said detecting of congestion.